Materials for inducing alignment in liquid crystals and liquid crystal displays

Reactive side-chain polymers within the class of polyimides, polyamic acids and esters thereof, comprising identical or different repeat units selected from one or more of the formula

• wherein L2 is a covalent bond or a linking group selected from the group of —O—, —S—, —NR1—, —O—CO—, —CO—O—, —NR1—CO—, —CO—NR1—, —NR1—CO—O—, —O—CO—NR1—, and straight-chain and branched-chain alkylenes represented by —(CH2)n—, —L3—(CH2)n—, —(CH2)n—L3, —L3—(CH2)n—L4—, each optionally mono- or poly-substituted by fluorine or chlorine and optionally chain interrupted by —O— or —NR1, wherein L3 and L4 are selected from the group of —O—, —S—, —NR1—, —O—CO—, —CO—O—, —NR1—CO—, —CO—NR1—, —NR1—CO—O—, —O—CO—NR1—, R1 is selected from the group of H and lower alkyl group and n is 1 to 20;
• L1 is selected from the group of L2, —NR2—, —NR2—CO—, —CO—NR2—, —NR2—CO—O—, —O—CO—NR2—, wherein R2 is selected from the group of H, lower alkyl group, and —D—L2—Cf;
• D is a divalent group containing 1 to 4 carbon-carbon double bonds, selected from the group of C3-C24 aliphatic, C3-C24 alicyclic, C8-C24 arylalkyl groups, all optionally substituted with 1 to 4 heteroatoms selected from the group of oxygen, nitrogen and sulfur and optionally mono- or poly-substituted by fluorine, chlorine or cyano, wherein the carbon-carbon double bond(s) are isolated from any other Π-system within the side-chain;
• Cf represents a monovalent C4 to C20 fluorocarbon radical;
• A is a trivalent unsubstituted or optionally fluoro-, chloro-, cyano-, alkyl-, alkoxy-, fluoroalkyl- or fluoroalkoxy-substituted aromatic or alicyclic group;
• B is hydrogen or a monovalent organic group derived from an alcohol after formal removal of the hydroxyl group;
• and
• M is selected from the group of
• wherein Z is independently selected from the group of a covalent bond, —O—, —S—, —NR1—, straight-chain and branched-chain alkylenes represented by —(CH2)n—, —L5—(CH2)n—, —(CH2)n—L5, —L5(CH2)n—L6—, each optionally mono- or poly-substituted by fluorine or chlorine and optionally chain interrupted by —O— or —NR1, wherein L5 and L6 are selected, independently, from the group of —O—, —S—, —NR1—, —O—CO—, and —CO—O—;
• and m is 1 or 0.